Well, it’s a bit more than “the general consensus.” It’s more like “every use on record except one website and you.”
Sounds to me like a classic case of “false etymology,” where people try to imagine how a word or phrase came to be and they supply something that sounds logical (“Hey, if you fold it ten times…”) without actually knowing the real origin of the word or term. False etymologies usually sound plausible and thus tend to get some traction in people’s minds.
Anyway, if you want to double the size of something ten times, that would be ten-unfold. Furthermore, it’s nigh impossible to fold a piece of paper in half more than seven or eight times, so as well as being just plain wrong, this etymology doesn’t even make sense, and is impossible.
I wouldn’t be surprised if it’s more than that. Unless his math teacher wrote that entry in that site, it has some traction.
Which is still the same usage as everyone else in this thread is saying. One e-folding is an increase by a factor of e, not by a factor of 2[sup]e[/sup]. And “60 e-foldings” is not the same thing as a “(60*e)-folding”.
The myth was that it’s impossible to fold a piece of paper more than seven times, but the Mythbusters were able to take a football field-sized piece of paper and fold it eleven times, albeit with the help of a steamroller and forklift, into about the size of a twin mattress.
As long as we’re on the subject of tens, the one that bugs the crap out of me is when the TV news people say something was decimated, when they really mean it was ruined or destroyed. Decimation shouldn’t be all that bad - originally, it’s just a reduction by 10%, but the dumbing-down of everything has changed it to now mean complete ruin.
That’s why I said nigh impossible. Certainly not easy enough for this etymology to work properly.
There was also a high-schooler (link will work tomorrow) who used her own muscle power to fold a piece of paper 12 times. It’s not a matter of strength; it’s just a matter of the length-to-thickness ratio of the paper (the student, Britney Gallivan, used unrolled toilet paper).
Your teacher was either (1) a crackpot, at least on this one issue, or (2) yanking your chain, or (3) free-associating and letting the word “ten-fold” lead to an observation on what would happen if you actually folded something ten times, and you mistakenly thought he was giving a serious definition of the word “tenfold.”
Actually I was taught that tenfold (or twofold or hundredfold) meant doubled ten (or two or onehundred) times as well. Due to the large difference between multiplying something 10 times and doubling something ten times, I always took it to mean multiplied (whether used correctly or not) and just never used the phrase myself.
I think the fact that there is a term ‘hundredfold’ demonstrates that it can’t reasonably mean 100 doubling operations. There can’t be very many everyday contexts in which it’s useful to talk about something increasing by a factor of 2[sup]100[/sup].